The move to create a so-called cap-and-trade system would be a substantial step by the world’s largest polluter to reduce emissions from major industries, including steel, cement, paper and electric power.

The announcement, to come during a White House summit meeting with President Obama, is part of an ambitious effort by China and the United States to use their leverage internationally to tackle climate change and to pressure other nations to do the same.

Joining forces on the issue even as they are bitterly divided on others, Mr. Obama and Mr. Xi will spotlight the shared determination of the leaders of the world’s two largest economies to forge a climate change accord in Paris in December that commits every country to curbing their emissions.